1. Field of the Invention
The present invention relates to an image forming apparatus, such as a facsimile machine, a copying machine, a scanner, a printer, or a composite machine thereof.
2. Description of the Related Art
An electrophotographic composite machine commonly includes a charge unit that charges the surface of a photoconductive drum evenly, an image writing unit that forms an electrostatic latent image by exposing light to the surface of the photoconductive drum based on an image data, a developer unit that develops an image by transferring toner to the electrostatic latent image, a transfer unit that transfers the toner image on a recording sheet that is carried along a recording sheet feed path, and a fuser unit that affixes the toner image on the recording sheet.
A series of processes is conducted, such as charging and exposing light to the photoconductive drum, developing, transferring the toner image to the sheet, and fusing. A recording sheet, which passes through a series of processes as described above, is placed on a sheet discharge tray after passing through the space in between a drive roller and a press roller including a sheet transportation unit.
First, an image recording apparatus includes a transfer unit that transfers a toner image to a recording sheet, a fuser unit that affixes the toner image on the recording sheet after the recording sheet passing through the transfer unit, a vertical feed path between the transfer unit and the fuser unit, a curved feed path between the fuser unit and a recording sheet outlet, and a recording sheet discharge tray that is formed on an upper surface of the apparatus. The recording sheet is arranged to be discharged upward at an angle from the recording sheet outlet for improving the ability of stacking the recording sheets.
Moreover, an image forming apparatus is known, which includes the recording sheet discharge tray in a space formed in between a reading part and a recording part for space saving. In the apparatus, the edge of the recording sheet may be curled when it touches the lower surface of the reading part that covers the upper surface of the recording part when the recording sheet is discharged.
Furthermore, in the widely-used image reading apparatus, a document supply tray is disposed on a document discharge tray and the trays are connected by a U-turn feed path, and an automatic document feeder (ADF) is provided for reading an image on a moving document at a read face that exists on the U-turn feed path by exposing light to the document. The document feed path is formed such that the recording sheet is curved and reversed in a smaller curvature radius than the one of the recording sheet feed path. Therefore, there is a possibility that the recording sheet is curled as the still warm sheet right after copying passes through the sheet feed path. Consequently, the recording sheet may also be curled parallel to the document feed direction in the image reading apparatus as well as the image recording apparatus as described above.